Comment 1 for bug 316540

There definitely seems to be a problem here, but I think your diagnosis is incorrect. The code in the traceback is invoking ServicesController.getUser(nick), which should return the User object that is associated with any user on the network. I believe the problem is that the code in question is trying to look up the User record by the old nickname, but this fails since the User object has already had the nick change applied; I think the solution is to look it up by the new nickname instead, but I only really glanced at the code, so don't take my word for it.